


Sweet Octopus

by Clockwork451



Category: Assassination Classroom
Genre: M/M, Non-Consensual Drug Use, Tentacles, Underage Drug Use
Language: English
Status: Completed
Published: 2019-01-02
Updated: 2019-01-02
Packaged: 2019-10-03 01:21:35
Rating: Explicit
Warnings: Rape/Non-Con, Underage
Chapters: 1
Words: 2,298
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17274413
Author URL: https://archiveofourown.org/users/Clockwork451/pseuds/Clockwork451
Summary: Nagisa has had a harder time than usual with his mother so tonight he decided to stay away for as long as possible.  Besides, the students of 3-E have been training for a couple months on how to assassinate their teacher so obviously, he could protect himself if anything happens.  A couple of someones decide to prove him wrong.





	Sweet Octopus

**Author's Note:**

> Hello everyone! I haven't written a story in like 4 and a half years so who knows if this will be good or not. I have found this series very lacking in Korosensei/Nagisa so here's a little something. I'm still working on the manga but I finished the anime so it will be anime based.
> 
> Enjoy!

It was the end of the school day and the students of 3-E were leaving the classroom after a good day of failed assassinations and studying. Korosensei was bidding each of his students a farewell before he disappeared, most likely to retrieve food or sweets from another country.

Kaede Kayano turned to Nagisa Shiota as he was putting his things into the cream-colored school bag. "Would you like to walk home together?" Kayano asked as Nagisa slipped the bag strap over his shoulder.

There was only a moment's hesitation as Nagisa thought about it. Last night was bad, his mother had forced him into a delicate dress and she was still in a bad mood the next morning. He threw up a fake smile and rubbed the back of his head. "Sorry, I need to use the restroom, why don't you go ahead and we'll walk together some other time?"

Kayano nodded, accepting the story with ease, and then waved goodbye before she left. Nagisa went into the men's room in case anyone was lingering and splashed some cold water onto his face. In reality, he wanted to wait as long as possible before going home

If he had left with Kayano he would have made it home in time for his mother to yell at him. She went to bed pretty early so if he lingered for a couple hours he might not have to see her tonight.

After drying off his face, Nagisa picked up his bag and peeked out of the bathroom. It looked empty.

Leaving the building Nagisa breathed in the fresh air and headed down the worn trail. This time he would go the long way around, it would give him an extra forty minutes of peace and his mother might have gone to bed.

Adjusting his shoulder strap, the blue-haired boy started home. The last couple of months had gone by so fast and Nagisa had gained confidence in his abilities. Lost in his own mind he didn't notice the hand from the dark alley grip his upper arm and yank him out of the view of the street.

Nagisa had let out a gasp before something strong smelling, tart and almost viscous, was filling his lungs. His head filled with cotton and his eyes rolled as he sagged in the hold of a man the same age as his father. He could feel his heart hammering against his ribcage as the second man in front of him swam in and out of view.

The blue-haired boy's cheeks turned pink as he felt his penis stiffen in the cuffed pants. "Well, well, look at that," laughed the older man holding him under his arms, "those Poppers _do_ work!" Nagisa was set down on the dirty alley ground and he was able to get a faint look at the older man who had grabbed him. He was missing teeth and starting to go bald.

"They don't last long," grunted the other older man. He had a crooked nose as if he had been in a lot of fights and a gut that proved he liked to drink. "My guy said we should make 'em drink it, but it might kill 'em." He shrugged and while Nagisa was still under the hypnotic effects of the vapor the liquid poured down his throat.

He coughed and turned his head but most of it slipped into his stomach. It was a couple of minutes before it started to work, giving the two older men enough time to strip him of his clothes. "Reo did mention they cum easy on this stuff," the man who had used the Poppers told the other as they both stared at Nagisa.

The blue-haired boy was lying on top of his clothes, undulating as his hard dick wept with what looked like an orgasm. The older man with the missing teeth huffed, "Can't have him ruining the fun before we start."

He yanked a hair tie from Nagisa's head, taking several blue strands with it, and then snapped it onto the base of Nagisa's penis, stopping the spillage. Grinning to themselves the two men opened their pants and stroked their penises.

The older man with the missing teeth got down and sucked on his middle and ring finger until they dripped. Once satisfied he shoved them knuckle deep into Nagisa's anus which had slackened because of the mind-altering drug.

All Nagisa could do was lie there and watch with glazed eyes as the missing teeth man removed his fingers and filled the boy with his dick. It only took a couple minutes before the man was shuddering like a beached fish and cumming inside of him.

On this end, Nagisa felt conflicted. The real him, which was under a heavy layer of drugs, hated everything about this and was glad it was over soon, but the drugged-out version of Nagisa wished it had lasted longer and could make him cum.

The second man, the one with the filled out gut, was only too happy to spread Nagisa open on his own dick. He didn't last much longer than the first guy. They took turns on his poor asshole and while one pounded him like ground meat the other was sucking and biting his nipples, causing them to turn red and swell with the abuse. All the while the hair tie around the boy's penis kept it hard and waiting.

It was now that Korosensei returned from Korea with several bags of sweets intent to eat them in one sitting. He smelled the strong scent of sex and drugs previous to seeing shiny blue hair. There was only one person he knew with hair like that and it put him on edge in an instance.

It took less than a second for Korosensei to end up behind both men. He was all shadows and darkness with sharp, pointed teeth and black slitted eyes stretched and cruel.

The two older men hadn't seen the tentacles, all they knew was fear and terror as they waved in the air, kicking and screaming and pissing themselves as Korosensei brandished them against the brick wall like well-done pasta. Sliding down the wall left blood smears and ick but unfortunately, the two men were still alive, only unconscious.

The absolutely furious creature turned his attention to Nagisa who was now spreading his legs wider and panting in wanton abandonment. Cum and blood dotted the puffy rim of his purple anus while nail and teeth marks bruised his legs and chest. Nagisa lifted both arms in a beckoning way.

" _Sensei~_ " He purred, sounding almost drunk as his long, dark lashes swept over his cheeks. "I want you _Ko~ro~sen~sei_." His name was delicately framed by pink lips which were kitten licked afterwards, leaving them wet and shiny.

Instead of a response, Korosensei parted his sharpened teeth, spittle dripping and steam rising from his dark mouth as he moved closer to the aroused boy. Despite his black, ferocious appearance the tentacle that circled Nagisa's slight frame was gentle. Two arms twirled around Korosensei's shoulders, cupping the back of his head as Nagisa pressed his lips to Korosensei's.

The kiss would have been awkward if the boy was in a better state of mind, but for right now he didn't care, all that mattered was tasting his sensei. There was the sweet taste of the candy Korosensei always ate before the tang of blood as Nagisa cut his tongue on the sharp teeth of the dark monster.

The smell and taste of blood made Korosensei act in a way that the drugged-out version of Nagisa thoroughly enjoyed. A single black tentacle found its way to his ready anus, stuffing him full in one go. The two-fingered tentacle broke the hair tie that had trapped his penis and stroked the shaft until Nagisa was ready to explode only to grip the base and prevent release.

Nagisa was getting louder, moaning and gasping, begging, pleading, tears at the corners of his bright blue eyes as he gazed up at his Korosensei. "Please, Korosensei, please, let me cum," he whimpered. Every time he neared release the octopus would stop it.

" **You are mine** ," the words dripped with dark, angry possession, filling Nagisa with burning arousal as he let himself get fucked over and over again. It felt like every single one of Korosensei's tentacles had tasted his insides by this point.

Korosensei brought Nagisa higher and he licked each wound covering his chest, spreading his own saliva and scent across the pale skin, removing most of the traces of the two older men. Nagisa brought them together again, mouth to curved mouth in a graceless kiss as a tentacle speared him deep and hard. As the thick globs of cum poured into every nook and cranny of Nagisa's insides the two-fingered tentacle stroked the human penis, finally letting Nagisa cum.

"Korosensei!" Nagisa gasped his name in a sweet, high-pitched voice as his head fell back, baring his throat. Sharp teeth seized his throat, not puncturing, but holding on in a threatening way; Nagisa liked it. As the pleasure started to fade and both people were catching their breath Korosensei turned back to his happy yellow color.

His tentacle slid out of Nagisa's abused rump, sperm gushing from his loose hole. In a flash, the octopus had picked up Nagisa's discarded clothes and the bags of sweets then vanished.

Nagisa came to his senses a little while later cradled by Korosensei, his head on the teacher's shoulder as thin, white tentacles roved his body. He blinked up at Korosensei and when their eyes met Nagisa looked away, face burning with embarrassment as he remembered what they had done.

"They drugged you," Korosensei supplied as the tentacles pulled away and set Nagisa on his feet. A yellow tentacle with Nagisa's laundered clothes pressed them into his hands. "You had no choice, do not think that this is your fault. I have cleared your system of the drug and checked that you were not given any disease by those two men."

Korosensei stood from his seated position, standing to his full height but still looking small as he rubbed the back of his head. "I am afraid to say that I also preyed on the situation. Seeing you so vulnerable and wanting, in my angered state I was unable to help myself. I can only hope that you will not hate me forever and can forgive your terrible sensei," he bowed to Nagisa.

Nagisa could still feel the two men violating him and yet the memory of Korosensei filling him to the brim more than overpowered it. He stared at his impossibly tall, incredibly strong sensei bowing to him and felt the warmth that grew in his chest from the act. The creature before him blew up the Moon and had all intentions of blowing up the Earth in a year but he asked for forgiveness because of this incident?

"I could never hate you, Korosensei," the words were barely more than a whisper but he knew that Korosensei would hear them. "Who knows what those men would have done when they were through," he shuddered to himself, realizing for the first time how bad that situation could have gone.

Nagisa set his hand on Korosensei's cheek and tilted his face up, looking into the beady eyes that expressed so much. "There's nothing to forgive," his smile was small, sweet. "Thank you for saving me, Korosensei." Nagisa leaned in and pressed a chaste kiss to the corner of Korosensei's smile, making the octopus turn soft pink with a blush.

Standing up straight, Korosensei scratched the side of his face. "Why don't you get dressed and I'll take you home?" Nagisa looked out the windows, noticing that it was pitch black outside. It was also at this point that he registered he was standing in the staff lounge of the mountaintop school.

He nodded and despite all that had happened between them Korosensei turned away, giving Nagisa some semblance of privacy. The blue-haired boy started to redress and as he did he checked the wounds on his body. Except there weren't any marks. It seemed as though Korosensei had healed his wounds, as well.

There was one place he couldn't check at the moment but he didn't feel any pain and so could only assume that Korosensei had healed his anus, too. It was embarrassing to think of but Nagisa was also grateful. Korosensei had removed every trace of those two men except for the memories and as long as he only thought of Korosensei in that situation then Nagisa knew he could work past this, too.

"I'm ready."

Korosensei turned back to Nagisa, bright and yellow with a large smile as usual. He fitted Nagisa into his teacher's robes and if Nagisa snuggled into his clothes neither said anything about it. His face pressed into the soft black and red clothes, noting that Korosensei smelled faintly of yuzu.

Within the next few seconds he was being removed from his teacher's clothes and set on his feet in front of his door. "Have a good night, Nagisa-kun," Korosensei stroked the blue hair that he loved so much and was gone.

Touching his head, Nagisa felt the twin pigtails and smiled to himself as he opened the door to his dark house. It had started as an awful night but his sensei had turned it around. It would take a long time for him to be able to deal with what happened but at least he was still alive to do so. He also knew that no matter what his sensei would be there to help. And hey, maybe next time they could forgo the drugs.

**Author's Note:**

> I needed more pissed off Korosensei in my life, that shit's fuckin' hot.


End file.
